Netbeans and eclipse are really good and agree with Zane on it. Netbeans particularally since you can add in c++ and a few others in the plugins for it. Also if you want as well there is Microsoft Visual Studio express as well that you can download if your heading through the windows environment. http://www.microsoft.com/visualstudio/en-us/products/2010-editions/express

GCC can either be compiled from source (available on http://gcc.gnu.org/), or you can use your local package manager. If you're on a Mac, GCC is part of the XCode developer package.

I can't think of anything else. IDE's are overrated; 99% of all the code I've ever written (and that's tens of thousands of lines in multiple languages) has been straight into Vim and compiled from the command line. IDE's just aren't necessary.